Inorganic Hydrides Used as Hydrogen Sources of Fuel Cell

A fuel cell is a kind of power generator which produces electricity by oxidizing hydrogen in oxygen or air. However, hydrogen is not easy to care for due to its being a very flammable and explosive gas.
Inorganic hydrides such as lithium borohydride (1), sodium borohydride (2), potassium borohydride (3), and lithium aluminum hydride (4) are relatively-stable crystals. The researchers have investigated fuel cells using them as hydrogen sources. For example, 2 reacts with water and generates hydrogen according to Scheme 1. But hydrogen generation is inhibited in alkaline aqueous solution, and can be regulated by using proper catalysts. In this case, the electrode reaction is represented by Scheme 2 and is able to extract electricity safely.